NNMREC Environmental Effects of Tidal Energy Outcomes of a
Scientific Workshop Brian Polagye University of Washington
Northwest National Marine Renewable Energy Center PICES 2010
October 26, 2010
NNMREC Typical Sites and Devices 2-4 m/s 20-60 m Foundation
Drive Train Rotor 5-20 m 10-30 rpm Gearbox-Generator Direct Drive
Generator Pile Gravity Base
NNMREC Environmental Assessment Framework Boehlert, G. and
Gill, A. Environmental and Ecological Effects of Ocean Renewable
Energy Development, Oceanography, 2010 Level 1 Level 2 Level 3
Level 4 Level 5 Type of Marine Renewable Energy Stressors Receptors
Level 6 Environmental Effect (frequency and duration) Environmental
Impact (type and severity) Cumulative Effects (scales and
context)
NNMREC Need for Workshop Major interest in developing
hydrokinetic energy in the U.S. Environmental compatibility of
technology stated without proof. Environmental uncertainties
present a major barrier to projects getting in the water at any
scale.
Slide 10
NNMREC Technology Scope Tidal Hydrokinetics Tidal Barrage River
Hydrokinetics
NNMREC Session Chairs Discussion 4 hours Receptors 2.5 hours
Stressors 1.5 hours Wrap Up 1.5 hours Plenary Sessions 4 hours
Stressors 2.5 hours Workshop Structure Day 1 Day 2 Day 3
Participant Feedback: Another day would have been useful
Slide 13
NNMREC Workshop Participants US West Coast (CA, OR, WA, AK) US
East Coast Europe Canada Universities Agencies/NGOs Research Labs
Industry Specific technical or scientific expertise Representative
distribution of affiliation Interest greatly exceeded capacity
Slide 14
NNMREC Relative Significance and Uncertainty Physical
environment: Near-field Physical environment: Far-field Habitat and
Invertebrates Fish: migratory Fish: resident Marine Mammals and
Seabirds Ecosystem Interactions Stressor element #1 Stressor
element #2 Color denotes significance Environmental receptor
Stressor element Low Medium High Unknown Not Applicable Symbol
denotes uncertainty ? Low Medium High Unknown
Slide 15
NNMREC Presence of Devices Static Effects Physical environment:
Near-field Physical environment: Far-field Habitat &
Invertebrates Fish: migratory Fish: resident Marine Mammals &
Seabirds Ecosystem Interactions Structure below water surface
Structure above water surface Disturbances from installation of
device Disturbances from installation of power cable Disturbances
from removal of device Disturbances from removal of power cable
Maintenance Pilot Scale
Slide 16
NNMREC Presence of Devices Static Effects Commercial Scale
Physical environment: Near-field Physical environment: Far-field
Habitat & Invertebrates Fish: migratory Fish: resident Marine
Mammals & Seabirds Ecosystem Interactions Structure below water
surface Structure above water surface Disturbances from
installation of device Disturbances from installation of power
cable Disturbances from removal of device Disturbances from removal
of power cable Maintenance
Slide 17
NNMREC Identification of Priority Interactions Selection
Criteria High potential significance High uncertainty Summarize Key
Information Description Gaps in Understanding Monitoring Approaches
Mitigation Measures (stressor only)
Slide 18
NNMREC Workshop Report Will be published as NOAA Tech Memo
Draft out for review to participants by end of week Details of
breakout sections Challenges indentified Recommendations
http://depts.washington.edu/nnmrec/workshop
NNMREC Project Environmental Data are Scarce Single device 5 m
diameter Installation effects only CleanCurrent Single device 2 x
16 m diameter Acoustic effects Marine mammal behavior Seabird
behavior Benthic habitat MCT Single device 6 m diameter Acoustic
effects Fish behavior Benthic habitat Open Hydro Array 5 m diameter
Fish behavior Seabird behavior Benthic habitat Verdant Power Single
device 3m diameter* Acoustic effects Marine mammal behavior Fish
behavior ORPC
Slide 21
NNMREC Information Needs at Pilot Scale StressorPriority
AreaBefore PilotDuring Pilot Presence of devices: static effects
Effects of static structures on benthic ecosystems Characterize
benthic habitat. Characterize species presence/absence and
behavior. Disruptions to benthic habitat installation/recovery.
Rate at which structures are colonized. Fish and marine mammal
interactions with modified benthic ecosystems. Presence of devices:
dynamic effects Potential for direct interactions of marine species
with turbine rotor Characterize movements of marine mammals, fish,
and seabirds at temporal and spatial scales required to assess
potential for direct interactions. Types of interactions and at
what frequency they occur.
Slide 22
NNMREC Information Needs at Pilot Scale StressorPriority
AreaBefore PilotDuring Pilot Chemical effectsApproaches to
preventing biofouling are poorly defined Assess potential impacts
of anti-fouling biocides. Fate of chronically released biocides.
Acoustic effectsBehavioral responses to increases in broad band
noise Behavioral response of species to acoustic signals.
Measurements of sound pressure levels from device operation.
Electromagnetic effects Electromagnetic fields from operating and
idle devices Laboratory studies of electric and magnetic fields.
Models of electric and magnetic fields from proposed devices.
Measurements of magnetic fields from energized cables and operating
devices.
Slide 23
NNMREC Challenges to Deploy and Monitor Monitoring technologies
are underdeveloped Existing methods focused on population effects
Existing methods may not function in tidal energy environments
Difficulty of predicting, detecting, and attributing changes to
tidal energy devices Legal protections or ethical considerations
prohibit studies of some interactions Some important effects can
only be measured at commercial scale
NNMREC Preliminary Research Prioritization Marine mammal-
device interactions Blade strike Acoustic effects Fish-device
interactions Environmental tipping points for energy removal 7
receptors x 6 elements x 7 stressors x 6 elements 1700 potential
interactions
Slide 26
NNMREC Pilot Projects are Required Recognized need by
participants of all affiliation Must be well-monitored Prioritize
objectives Use common protocols Courtesy of Marine Current
Turbines
Slide 27
NNMREC Develop Assessment Capabilities Close monitoring
instrumentation gaps Detect, classify, and identify marine
organisms at a variety of scales Real-time monitoring for decision
making General monitoring protocols Objective of data collection
Type of data to be collected Mechanisms for data collection
Numerical models Turbine scale: hydrodynamics, fish interactions
Regional scale: tipping points
Slide 28
NNMREC Mitigate Impacts when Possible StressorPriority
AreaRecommended Mitigation Presence of devices: static effects
Effects of static structure on benthic ecosystems Minimize anchor
sizes. Minimize number of moorings and slack lines. Streamline
support structures. Presence of devices: dynamic effects Potential
for direct interactions of marine species with turbine rotor
Increase visibility of rotors to fish. Acoustic avoidance measures.
Shock absorbers on leading edges of blades. Temporary device
shutdown. Electromagnetic effects Behavioral disruption from
electric and magnetic fields Bury power cables. Twist cores for AC
cables. Run DC cables of opposing polarity in close proximity.
Cumulative effects Effects on large, mobile species Limit number of
devices at a given location until effects of operation are
sufficiently understood.
Slide 29
NNMREC Collaboration is Essential Information needs to be
shared between projects IEA-OES Annex IV Significant intellectual
property concerns Hydrokinetic industry needs to engage with the
oceanographic community Leverage active areas of research Expand
opportunities for interdisciplinary collaboration
Slide 30
NNMREC Acknowledgements Workshop organizing committee Andrea
Copping, Pacific Northwest National Laboratory Keith Kirkendall,
NOAA Fisheries George Boehlert, Oregon State University Michelle
Wainstein, University of Washington Sue Walker, NOAA Fisheries Brie
Van Cleve, Pacific Northwest National Laboratory Workshop sponsors
NOAA Fisheries US Department of Energy Workshop participants,
particularly session chairs and note takers